This invention relates generally to electrical interconnect structures, and more particularly the invention relates to interconnects which are subject to compressive and/or expansive forces in application.
Solar cell modules are used in high altitude and space applications where temperature subjects the modules to shrinkage. Further, in some applications planar arrays of solar cell submodules are packaged in a laminate structure between two layers of laminate material which shrink during packaging. The planar arrays are submodules containing a plurality of semiconductor substrates in which the solar cells are fabricated, and the substrates are serially electrically connected between bus bars which receive solar generated voltages. The interconnects typically comprise a metal layer of foil which is soldered or welded to contacts on adjacent substrates or between a substrate and a bus.
The shrinkage of the packaged modules can cause buckling of the metal foil interconnects and create ripples or an unevenness in the surface of the planar arrays. In some space applications the unevenness has deleterious effects. Heretofore, a through hole pattern has been used in foil interconnecting two substrates to reduce buckling, but the peripheral or bus interconnect must be a solid foil which does not permit use of the through hole pattern. Attempts at reducing buckling of the peripheral interconnect by embossing or by folding the foil have not been successful.
The present invention is directed to providing a metal foil peripheral or bus interconnect which reduces buckling when subjected to expansion and shrinkage.